Generally, tents or sleeping bags are used for camping at outdoor places such as mountain, riverside, and seashore for climbing and fishing.
In this case, people lay a plastic or vinyl mat on the ground to interrupt chill and moisture from the ground.
Nevertheless, it is difficult to maintain the body temperature in a situation of severe cold such as winter climbing or alpine climbing. Unless the body temperature is appropriately maintained during camping, judgment and ability to cope with a crisis may be affected, causing a serious accident.
In order to overcome the above problems, Korea Utility Model Registration No. 207,192 and Korea Patent Registration No. 604,405 disclose a water heater for a heating mat and a portable boiler, respectively. However, since the water heater for the heating mat and the portable boiler do not include a separate temperature controller for controlling the temperature of circulating water that circulates in a heating mat and a hot water floor mat, a user may be burned by the circulating water of increasing temperature.
Also, since gas bubbles of high pressure generated during heating of the circulating water cannot be discharged and circulate along a pipe and a hot water hose together with the circulating water, the gas bubbles may hit against the inner surface of the pipe and the hot water hose, causing a noise.